Wow. Very big question with a ton of variables. I would recommend a few books to absorb.
First off, consider the possible: If you want to beef up a Hughes 38 to offshore standards, read this:
Secondly, while the Hughes 38 is "coastal", it's also designed by S&S, meaning it's got a reasonable pedigree.
Thirdly, Cap'n Fatty would seem to be a very good sailor. A very good sailor can get the most out of a boat, without pushing it so hard that important things (or crew) break. You may wish to copy not only his boat improvement projects, but his career. When we here of Catalinas and Hunters circling the globe, we have to look at the qualities of the skipper first, because I don't care what your opinion is, these boats weren't created to cross the open ocean, and while they might do so from time to time, it would have to be in the care of a skipper who had a lot of experience and even more prudence.
Stronger-built, or perhaps purpose-built, bluewater cruisers provide a cushion of structural integrity and design elements that insulate the less-experienced skipper from bad decisions.
I have found Ferenc Mate's books, and this book:
helpful in allowing me to visualize the stresses and knocks heavy weather can impose on a boat. I bought my cruiser on the basis that it will forgive my tactical errors to a point.
Attributes to seek is too broad and contentious a topic.
Attributes to avoid? Insufficient tankage, lack of spares, too wide cabin, insufficient handholds, grab bars, pad eyes, undersized rigging, unreinforced sails, undersized ground tackle, lack of variety in ground tackle, lack of properly sized rode, insufficient stowage that is insufficiently secured, redundancy in pumps (manual and electric), windlass (manual and electric), beefy battery and charging systems, clearly marked everything (I just bought a Dymo label maker and have been labelling everything I've disconnected on my diesel prior to overhauling), robust but compact refrigeration (keep it full, but don't count on it for all your food), radar, robust fuel filtering, SSB/satellite phone, separate GPS/chartplotter, tinned wires...man, I could type all night.
Ask people who have COME BACK what works and what doesn't, and what turns out to be a very good idea, and what failed on Day Three.
I've raced against Hughes 38s, as there are a few of them here in Toronto, on my Viking 33. They seem sturdy enough, if a little plodding, but plodding, in a blue water context, has something to recommend it.